Third Reich
After 1933, like all German universities, it was affected by the Nazi regime. The rector during this period was Eugen Fischer. It was from the university's library that some 20,000 books by "degenerates" and opponents of the regime were taken to be burned on May 10 of that year in the Opernplatz (now the Bebelplatz) for a demonstration protected by the SA that also featured a speech by Joseph Goebbels. A monument to this can now be found in the center of the square, consisting of a glass panel opening onto an underground white room with empty shelf space for 20,000 volumes and a plaque, bearing an epigraph from an 1820 work by Heinrich Heine: "Das war ein Vorspiel nur, dort wo man Bücher verbrennt, verbrennt man am Ende auch Menschen" ("That was only a prelude; where they burn books, they ultimately burn people").
The Law for the Restoration of the Professional Civil Service (German "Gesetzes zur Wiederherstellung des Berufsbeamtentums") resulted in 250 Jewish professors and employees being fired during 1933/1934 and numerous doctorates being withdrawn. Students and scholars and political opponents of Nazis were ejected from the university and often deported. During this time nearly one third of all of the staff were fired by the Nazis.
Read more about this topic: Humboldt University Of Berlin